Influence of dietary oils rich in omega-6 or omega-3 fatty acids on rumen microbiome of dairy cows

Abstract

The objective of this study was to compare the effect of supplementing dairy cow diets with contrasting sources of omega-6 (soybean oil) and omega-3 (fish oil) PUFA on rumen microbiome. For 63 days, 15 mid-lactating cows were fed a control diet (n = 5 cows; no fat supplement) or control diet supplemented with 2.9% DM of either soybean oil (SO; n = 5 cows) or fish oil (FO; n = 5 cows). Ruminal contents were collected on days 0, 21, 42 and 63 for 16S rRNA gene sequencing. Beta diversity and Shannon, Simpson and Chao1 diversity indices were not affected by dietary treatments. In terms of core microbiome, Succiniclasticum, Prevotella, Rikenellaceae_RC9_gut_group and NK4A214_group were the most prevalent taxa regardless of treatments. Bifidobacterium was absent in SO diet, Acetitomaculum was absent in FO, and Sharpea, was only detected in SO. Overall, results showed that at 2.9% DM supplementation of either SO or FO over 63 days in dairy cow diets does not cause major impact on bacterial community composition and thus is recommended as feeding practice.

Insights into Effects of Combined Capric and Lauric Acid on Rumen Bacterial Composition

“…Our findings show that the C10 + C12 treatment did not alter bacterial diversity, evenness, or richness ( Table 1 ), contradicting our initial hypothesis. The lack of effects on the overall bacterial indices could be explained by the low doses of MCFA (0.8% DM) [ 18 ]. Our results further agree with those of Burdick et al [ 8 ], who used comparatively lower doses of MCFA (0.25% DM; blend of C8, C10, and C12).…”